CVE-2026-64514

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An issue exists in the userfaultfd mechanism where the functions userfaultfd must wait() and userfaultfd huge must wait() read the Page Table Entry (PTE) without acquiring the page table lock before applying pte write() or huge pte write(). Because these accessors only decode bits from the present encoding, they may read offset bits from swap or migration entries, leading to undefined results. This can cause a thread to incorrectly believe a fault is still write-protected (WP-blocked) and remain asleep indefinitely while waiting for a UFFDIO WAKE signal that may never be sent.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.